Question

14) Find the eq. of the circle touching the line x-2y=3 at (-1,-2) and having a radius of sqrt. of 5
22) Find the eq. of the tangent line to the circle x^2+y^2-4x-6y+5=0 perpendicular to x-y=7.

Answer 1

I gave u a procedure for your other problem

http://openstudy.com/groups/mathematics/updates/4e4908a70b8b8d00ebe1da86

Answer 2

The first one is straightforward, the perpendicular goes through the center.

Answer 3

I'll do the other in a bit (if no-one else does).

Answer 4

Start by getting the equation in usual form so centre (2,3) and radius root 8

Do a sketch ( http://www.wolframalpha.com/input/?i=plot+%28x-2%29^2+%2B+%28y-3%29^2+%3D+8%2Cx-y+%3D+7).

U can see there will be 2 tangent lines.